1. Field of the Invention
The present invention relates to the arrangement of an integrated circuit on a multi-layer through contacting circuit board with bonding-wires extending between chip connectors and substrate connectors or terminals; especially for a compact circuit assembly of signal processors utilized in airborne bodies, generally as disclosed in U.S. Pat. No. 4,698,729, which is commonly assigned to the assignee of the present application.
2. Discussion of the Prior Art
An arrangement of that type is essentially known from the disclosure of European Laid-Open Patent Appln. 0 272 046 or from PCT-Publication WO 87/01510. The circuit board which is constructed in multi-layers and which is selectively contacted between the planes of the conductive paths thereof through the intermediary of electrically-conductive through-holes or vias; such as are disclosed in European Laid-Open Patent Appln. 0 220 508; possesses a depression with recessed sidewalls in the chip mounting region, wherein the steps formed by the recessed sidewalls are given by the different substrate planes of the circuit board and are equipped with contacts or terminals for the bonding-connections with the circuit terminals. Because of this staggering transversely of the boundaries of the circuits, a larger number of substrate contacts can be arranged along the boundary than in contrast with a narrow strip extending along the boundary of the circuit. In providing for the broad staggering, it is advantageous that the substrate contacts or terminals can be designed to be so large in their cross-sectional surface area, as to be able to concurrently serve as end surface regions for the associated through-holes or vias in the sandwich-plane of the circuit board which is desired for to the particular technological circuitry. However, disadvantageous is not only the requirement for a large space extending about the circuit, which essentially prohibits a close arrangement of circuits on the circuit board; above all, it is disadvantageous that for the placement of the bonding-wires from the contact plane of the circuit into planes on the circuit board which are offset with regard thereto, there cannot be utilized the commonly employed bonding devices, and that due to the path of the relatively large arches at small side spacings for the bonding-wires which bridge thereover, this results in an increased danger of short-circuiting. Basically, in view of the foregoing, it is intended to arrange the substrate contacts or terminals all in one plane, and always closely adjacent the circuit contacts, such as is known from the usual chip-bonding technology for small or miniature circuits. However, for high-integrated large circuits, such a large number of bonding-contacts are provided along their boundaries, that the geometrically associated and closely adjoining substrate contacts cannot be constructed large enough for the formation of the wiring-accommodating through-hole or via into the interior of the layered circuit board.